การกำจัดไดโคลฟีแนคด้วยสลัดจ์จากโรงบำบัดน้ำเสีย: ผลของไอออนโลหะและการศึกษาในถังปฏิกรณ์ชีวภาพแบบชั้นตัวกลางเคลื่อนที่

Abstract

Diclofenac (DCF) is one of the anti-inflammatory drugs widely used in households, which leads to its contamination in wastewater. Because DCF degradation in wastewater has not been clearly understood, there is a possibility that DCF may not be completely degraded in the conventional wastewater treatment plant. This research aims to study the efficiency of DCF removal in wastewater with the addition of sludge from Chiang Mai University wastewater treatment plant. Also, the effect of metal ion addition on the DCF removal efficiency and the DCF removal by a moving bed bioreactor (MBBR) treatment system were studied. Results from batch experiments with the DCF concentrations of 0, 0.1, 0.5, 1, 5, and 10 mg/L in the wastewater with and without the sludge (3.3 g) showed that the removal of DCF in wastewater alone was less than 50%. On the other hand, more than 90% removal of DCF was observed in wastewater with sludge addition. It can be implied that DCF in municipal wastewater may not be degraded, but it should be removed in the activated sludge system. The effects of metal ions at the concentrations of 0.25, 0.5, 0.75, 1, and 2 mg/L on the DCF removal showed that the removal efficiency increased slightly by some metal ions, which are still inconclusive. The final experiment in an MBBR reactor with 1 mg/L of DCF showed that the sludge addition at the startup of the reactor could increase the DCF removal efficiency to 28.51%, which was higher that the reactor startup with only wastewater, and this efficiency was slowly decreased until the end of 21 days of the experiment.